The present invention relates to connecting arrangements in general, and more particularly to an arrangement for interconnecting the adjacent upright marginal portions of wall components to form unitary box-shaped support structures or containers.
There have already been proposed various structures, which will hereafter be referred to as a support structure regardless of whether they are frameworks, containers, supports or otherwise, which, for the sake of a rapid assembly and partial or complete disassembly, are equipped with connecting arrangements which connect the components of the support structure to one another. More particularly, there has been already proposed a multitude of constructions in which the components of the support structure are connected to one another by means of connecting projections of some of the components which are received and arrested in position in slots of the remaining components. Thus, for instance, it is already known to provide the connecting slots as well as the connecting projections at the respective upper and lower regions of the components to be connected which assume upright orientations at least during the assembly of the support structure. Then, it is also known to let the upper connecting slots open onto the upper end face of the respective component, and to let the lower connecting slots open onto the respective side face of the respective component as considered in the assembling position of the component. Then, it has also been already proposed to provide means for arresting the lower connecting projections in the lower connecting slots.
The connecting arrangements of this type find a particular utility in such support structures as pallet frames which, among others, serve as supports for flat pallets or as constituent parts of so-called lattic box pallets. The walls or wall components of such a support structure can be constituted by lattice work or a network which is circumferentially reinforced by interconnected horizontal and vertical beams. However, the wall components can also be solid, that is, complete and imperforate so that the assembled support structure will constitute a container. Whether the support structure takes the form of a cage or of a container, it can be used not only for support or storage purposes, but also for transportation, delivery and provisioning.
However, it will be appreciated that the support structures of the above-mentioned type could also be used otherwise. For instance, a support structure of this type could be advantageously used as a super structure of a truck or a trailer.
In support structures of this type, at least one of the wall components of the support structure is dismountably supported on the remainder of the support structure. Particularly in support structures of parallelepiped configurations, however, it is already known to releasably connect the two side walls, on the one hand, and the front and rear walls, on the other hand, to one another. Then, two oppositely arranged ones of the above-mentioned walls are used as primary walls, and the two remaining secondary walls are then releasably mounted on the primary walls and arrested in position relative thereto. The primary walls usually are provided with the above-mentioned slots while the secondary walls usually have the above-mentioned connecting projections.
In one of the conventional support structures of the above-mentioned type, the upper connecting slots are provided in the upright marginal portions of the primary walls and each of them is shaped as a vertical slot which is adjoined by and communicates with a recess, while each of the lower slots is configurated as a horizontal slot which is adjoined by and communicates with another recess. The width of the respective slot, on the one hand, and the dimensions of the recesses, on the other hand, are so selected that the connecting projections which project normal to the respective side faces of the secondary wall components and which have annular collars at the respective free ends thereof can be introduced into the slots where the collars are received in the recesses. The play between the connecting projections and the slots, on the one hand, and between the collars and the recesses, on the other hand, is kept relatively low.
When the connecting projections of the respective secondary wall are introduced into the upper, vertically extending, slots of the neighboring primary walls, these upper connecting projections constitute a pivoting axle for this secondary wall so that the secondary wall can be pivoted thereabout in the downward direction until the lower connecting projections are introduced into the horizontally extending slots of the primary walls. For the purpose of arresting the secondary wall in position, arresting members having respective gripping portions are provided at the additional recesses which are associated with the lower slots, the arresting members being pivotable about the axis of the lower connecting projections in their fully inserted positions. The arresting members are thus capable of fixing the lower connecting projections in their fully introduced positions within the lower slots and in the additional recesses and, consequently, of preventing the upper connecting projections from sliding out of the upper slots of the primary walls.
The above-discussed connecting arrangement for the support structure can be used in a variety of ways. After the arrest of the lower connecting projections in their associated lower slots, the components of the support structure are positively connected to one another so that the shape of the support structure will not change during the subsequent handling of the support structure. The support structure can be, for instance, lifted at each of its constituent walls, without impairing the connection of the walls to one another. In addition thereto, the known connecting arrangement has the advantage that the assembled support structure can be lifted, turned or rotated in any desired manner without fear of disintegration of the support structure. A support structure of this type can also be used for storing and transporting bulk materials. Then, it is possible to discharge the bulk material from the interior of the support structure by tilting the support structure and by releasing the arresting members holding one of the secondary walls in position so that the affected secondary wall can now be pivoted about the upper connecting projections thereof while the first support structure remains otherwise intact. Furthermore, it is possible to fully pivot the secondary wall, subsequent to the discontinuance of the arresting action of the arresting members associated therewith, so that an easy access is obtained into the interior of, for instance, a pallet frame, even when the latter is arranged in a high-shelf storage intermediate other pallet frames. In view of the fact that the upper connecting projections remain connected to the neighboring primary walls of the support structure even under these circumstances, that is, when the respective secondary wall is pivoted about the upper connecting projections, the support structure remains stable.
However, notwithstanding the undoubtedly existing advantages of the above-discussed connecting arrangement and the support structure equipped therewith, experience has shown that it is disadvantageous in some respects and, hence, that it should still be improved so as to avoid such disadvantages. The reasons for this desired improvement are to be found, on the one hand, in the manufacturing considerations and, on the other hand, in the utilization or handling of the connecting arrangement.
The reasons which are in this connection to be found in the manufacturing considerations, include the substantial expense of the conventional connecting arrangement which is, to a great extent, attributable to the manufacture of the pivotable arresting members and their mounting on the primary walls. The limited play which is necessary for the assurance of the proper function of the pivotable arresting members calls for accurate manufacturing procedures and, hence, for the utilization of corresponding precise and, hence, expensive machines and arrangements which can be operated only by correspondingly trained personnel. Another factor which contributes to the rather high expense of the conventional connecting arrangement is to be found in the additional material and labor consumption which goes with the provision of the arresting members of the conventional connecting arrangement.
With respect to the utilization or handling considerations which render the conventional connecting arrangement less than perfect, it is to be mentioned that the mentioned conventional connecting arrangement does not sufficiently take into account the human imperfection. More particularly, lack of experience or of the proper attitude, or shear laziness on the part of the handling personnel, may result in a situation where, when the support structure has a disadvantageous position, such as, for instance, when the access to the arresting members is somewhat difficult, the arresting members, or one of them, are not fully or not at all actuated in their arresting sense. However, it will be appreciated that an improper arresting action of the arresting members cannot assure the integrity of the support structure during the handling thereof.
Furthermore, the movability of the pivotable arresting member may become impaired. The cause of this impairment may be the soiling of the connecting arrangement on or at the arresting members. However, it is also possible that the arresting members will freeze in their positions, for instance, when the support structure is used in cold storage facilities. When this happens, the handling of the affected arresting members will be impossible, at least for a limited period of time. Moreover, it can be imagined that, due to an improper handling of the arresting members and/or to the subjection thereof to improperly oriented or excessive forces, the arresting members will be damaged to such an extent that they will not be capable of moving within the recesses and thus their operation will be discontinued. In addition thereto, experience has shown that the above-mentioned gripping portions of the arresting members, which project beyond the outer contour of the support structure proper, have a detrimental influence during the handling of the support structure. Thus, it is possible not only that clothing articles or overalls of persons handling or passing by the support structure may become caught on the projecting gripping portions of the arresting members, but also that such persons may suffer an injury, particularly when the gripping portions have been so damaged that sharp edges or other sharp projections are present thereon. Finally, the presence of the projecting gripping portions of the arresting members requires the handling personnel to pay close attention to the support structure during the stacking, unstacking and other handling thereof.